Negative Resist Composition for Immersion Lithography
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Solution Overview
Problem
Current negative resist compositions for immersion lithography face challenges in achieving high hydrophobicity and favorable lithography properties, particularly when used with water as the immersion medium, as they require a balance between hydrophobicity and alkali solubility, which affects exposure speed and productivity.
Innovation Solution
A negative resist composition incorporating a fluorine-containing resin component with specific structural units and an alkali-soluble resin component, along with an acid generator and cross-linking component, to form a resist film with high hydrophobicity and improved lithography properties, including enhanced water tracking ability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a fluorine-containing polymeric compound is used as a base resin for a positive resist composition, then water repellency and transparency are improved, but a large quantity of out-gas is generated following exposure and etching resistance is unsatisfactory
Solution Approach 1:
The patent changes the chemical structure parameters of the fluorine-containing resin by specifying particular structural units (formula f1 with fluorinated alkyl groups and formula f2 with alkali-soluble groups) to reduce out-gas generation while maintaining water repellency. The molecular weight and structural composition are optimized to balance etching resistance and gas evolution characteristics.
Solution Approach 2:
The patent creates a composite resist system by combining the fluorine-containing resin (providing water repellency and transparency) with an alkali-soluble resin (providing etching resistance and reduced out-gas). This composite approach allows each component to contribute its advantageous properties while compensating for the weaknesses of the other.
2Productivity
If the resist film is rendered hydrophobic to improve water tracking ability, then exposure speed is improved, but resolution and sensitivity deteriorate and scum generation increases
Solution Approach 1:
The patent applies local quality by creating a resist film with differentiated properties: the surface layer possesses hydrophobic characteristics (from fluorine-containing resin) for improved water tracking and exposure speed, while the bulk maintains alkali solubility (from alkali-soluble resin) for proper development and pattern formation. This spatial differentiation of properties resolves the contradiction between hydrophobicity and resolution.
Solution Approach 2:
The patent optimizes the concentration ratio of fluorine-containing resin to alkali-soluble resin, and adjusts the molecular weight and structural parameters of both components to achieve the optimal balance between surface hydrophobicity (for exposure speed) and bulk solubility (for resolution).
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The composition achieves high hydrophobicity at the film surface while maintaining favorable lithography properties, such as resolution and etching resistance, thereby improving exposure speed and productivity in immersion lithography.
Implementation Method 1
a fluorine-containing resin component (F) containing a structural unit (f1) represented by general formula (f1-0)... R7 represents a fluorinated alkyl group
Implementation Method 2
an acid generator component (B) that generates acid upon exposure
Implementation Method 3
an alkali-soluble resin component (A)... a structural unit (f2) having an alkali-soluble group
Implementation Method 4
a cross-linking component (C)
Data Source
AI summary
A negative resist composition including:a fluorine-containing resin component (F) containing a structural unit (f1) represented by a general formula (f1-0) shown below, and a structural unit (f2) having an alkali-soluble group,an alkali-soluble resin component (A) excluding the fluorine-containing resin component (F),an acid generator component (B) that generates acid upon exposure, anda cross-linking component (C).[wherein, R7 represents a fluorinated alkyl group, and a represents either 0 or 1.]